Governments arent going to invest the countless billions of dollars it would take to develop a program that would successfully divert an asteroid on a 1:45000 chance. By the time something like this becomes a certainty, theres a good chance it will be too late to develop anything.
I’d guess that if a large asteroid is headed to hit the earth in 30 years, theres a 15% chance that we will be able to divert it.